Compatible with the maker's electric floor-warming mats, the Nuheat Cable System(PDF) lets users extend radiant floor heating into intricate and even wet spaces, including shower stalls, benches, saunas, and platforms. The 3/16-inch- thick components add a minimal increase in floor height, says the company. The energy-efficient system generates only 12 watts per square foot and can be controlled with the manufacturer's programmable thermostats. 800-778-9276.